The conventional manner of positioning a chisel or cutting insert on the insert holder of a rotary cutter, such as a router bit, a milling cutter or a planer head, is by abutting a precision ground surface located on the rear and side edges of the cutting insert against a precision ground backing reference surface provided on the insert holder's body. One of the shortcomings of such a system is that the entire cutting tool must be repositioned relative to the workpiece every time the cutting edge of the profiled insert is sharpened. This is a time consuming process. The adjustment of the overall cutter head position relative to the workpiece compensates for the amount of material removed from the insert's worn edge. This adjustment is effected so that the workpieces being machined are in dimensional tolerance, one to the other from one work cycle to the next.
The re-profiling or sharpening of a cutting insert implies removal of material from the insert and thus it results in a reduction of the weight of the insert. Applicant has found that there is a need to easily recalibrate the weight of a re-profiled insert to its original value after a sharpening or re-profiling operation has been conducted.
The backing surface of the holder body offers resistance against the cutting pressure, which is in a direction opposite the movement of the cutting tool, transferred to the cutting insert during operation. A front clamping member is provided at the front of the cutting insert, relative to the movement of the cutting tool, in order to firmly press the cutting insert against the backing surface of the holder body. One of the shortcomings of such a system is that the backing surface of the insert holder has to be profiled according to the cutting edge profile of the cutting insert. Accordingly, different insert holders must be provided for different profiles of cutting inserts.
It would be advantageous to be able to use the same rotary cutter head for different cutting insert profiles.